Actors Debra Winger and Mark Ruffalo joined hundreds of opponents of natural gas drilling in the Delaware River watershed who are demonstrating in New Jersey's capital.

They marched to the Statehouse after gathering at Trenton's War Memorial Monday, where the Delaware River Basin Commission had been set to vote on regulations regarding hydraulic fracturing, or fracking.

The commission canceled the meeting after Delaware's governor said he would oppose the draft rules. New York is also opposed. The regulations need three votes to pass. New Jersey and Pennsylvania are likely "yes" votes.

It is uncertain how the Army Corps of Engineers, another commission member, is planning to vote.

Activists say fracking would threaten drinking water for 15 million users. Drilling supporters say it would not harm water supplies.

(Copyright 2011 by The Associated Press. All Rights Reserved.)